With input from scientists around the world, American and European scientists working on the potential next new mission to the Jupiter system have announced their joint vision for the Europa Jupiter System Mission to explore "the emergence of habitable worlds around gas giants."

The proposed Europa Jupiter System Mission would provide orbiters around two of Jupiter's moons: a NASA orbiter around Europa called the Jupiter Europa Orbiter, and an ESA orbiter around Ganymede called the Jupiter Ganymede Orbiter.

"We've reached hands across the Atlantic to define a mission to Jupiter's water worlds," said Bob Pappalardo, the pre-project scientist for the proposed Jupiter Europa Orbiter, who is based at NASA's Jet Propulsion Laboratory. "The Europa Jupiter System Mission will create a leap in scientific knowledge about the moons of Jupiter and their potential to harbor life."

The new reports integrate goals that were being separately developed by NASA and ESA working groups into one unified strategy.

The proposed mission singles out the icy moons Europa and Ganymede as special worlds that can lead to a broader understanding of the Jovian system and of the possibility of life in our solar system and beyond. They are natural laboratories for analyzing the nature, evolution and potential habitability of icy worlds, because they are believed to present two different kinds of sub-surface oceans.

The Jupiter Europa Orbiter would characterize the relatively thin ice shell above Europa's ocean, the extent of that ocean, the materials composing its internal layers, and the way surface features such as ridges and "freckles" formed. It will also identify candidate sites for potential future landers. Instruments that might be on board could include a laser altimeter, an ice-penetrating radar, spectrometers that can obtain data in visible, infrared and ultraviolet radiation, and cameras with narrow- and wide-angle capabilities. The actual instruments to fly would be selected through a NASA competitive call for proposals.

The deepest ocean on Earth is the Pacific Ocean's Marianas Trench, which reaches a depth of 6.8 miles awesomely trumped by the depth of the ocean on the Jupiter's moon, Europa, which some measurements put at 62 miles. That's deep!

Although Europa is covered in a thick crust of scarred and cross-hatched ice, measurements made by NASA's Galileo spacecraft and other probes strongly suggest that a liquid ocean lies beneath that surface. The interior is warmed, researchers believe, by the tidal stresses exerted on Europa by Jupiter and several other large moons, as well as by radioactivity.

Most scientists believe that the subEuropan seas are locked under tens of kilometers of ice. Heat is then conducted from the warm core by bulk convective motion of ice - huge chunks of frozen material literally carrying the heat away with them as they move up through the icy layer, shuffling and refreezing as they dump heat into space.

But Jupiter's Europa might not only sustain, but foster life, according to the research of University of Arizona's Richard Greenberg, a professor of planetary sciences and member of the Imaging Team for NASA's Galileo Jupiter-orbiter spacecraft.

Europa, similar in size to Earth's moon, and has been imaged by the Galileo Jupiter-orbiter spacecraft. Its surface, a frozen crust of water, was previously thought to be tens of kilometers thick, denying the oceans below any exposure. The combination of tidal processes, warm waters and periodic surface exposure may be enough not only to warrant life, but also to encourage evolution.

With Jupiter being the largest planet in the solar system, its tidal stresses on Europa create enough heat to keep the water on Europa in a liquid state. More than just water is needed to support life. Tides also play a role in providing for life. Ocean tides on Europa are much greater in size than Earth's with heights reaching 500 meters (more than 1,600 feet). Even the shape of the moon is stretched along the equator due to Jupiter's pull on the waters below the icy surface.

The mixing of substances needed to support life is also driven by tides. Stable environments are also necessary for life to flourish. Europa, whose orbit around Jupiter is in-sync with its rotation, is able to keep the same face towards the gas giant for thousands of years. The ocean is interacting with the surface, according to Greenberg, and "there is a possible that extends from way below the surface to just above the crust."

"The real key to life on Europa," Greenburg adds, "is the permeability of the ice crust. There is strong evidence that the ocean below the ice is connected to the surface through cracks and melting, at various times and places. As a result, the , if there is one, includes not just the liquid water ocean, but it extends through the ice up to the surface where there is access to oxidants, organic compounds, and light for photosynthesis. The physical setting provides a variety of potentially habitable and evolving niches. If there is life there, it would not necessarily be restricted to microorganisms."

Tides have created the two types of surface features seen on Europa: cracks/ridges and chaotic areas, Greenberg said.The ridges are thought to be built over thousands of years by water seeping up the edges of cracks and refreezing to form higher and higher edges until the cracks close to form a new ridge.

The chaotic areas are thought to be evidence of the melt-through necessary for exposure to the oceans.

The tidal heat, created by internal friction, could be enough to melt the ice, along with undersea volcanoes - a combination of factors would give organisms a stable but changing environment -- exactly the type that would encourage evolution.

Ganymede is thought to have a thicker ice shell, with its interior ocean sandwiched between ice above and below. ESA's Jupiter Ganymede Orbiter would investigate this different kind of internal structure. The Jupiter Ganymede Orbiter would also study the intrinsic magnetic field that makes Ganymede unique among all the solar system's known moons. This orbiter, whose instruments would also be chosen through a competitive process, could include a laser altimeter, spectrometers and cameras, plus additional fields-and-particles instruments

The two orbiters would also study other large Jovian moons, Io and Callisto, with an eye towards exploring the Jupiter system as an archetype for other gas giant planets.

NASA and ESA officials gave the Europa Jupiter System Mission proposal priority status for continued study in 2009, agreeing that it was the most technically feasible of the outer solar system flagship missions under consideration.

Over the next few months, NASA officials will be analyzing the joint strategy and awaiting the outcome of the next Planetary Science Decadal Survey by the National Research Council of the U.S. National Academies. That survey will serve as a roadmap for new NASA planetary missions for the decade beginning 2013.

Image below shows NASA's Jupiter Europa Orbiter which will carry a complement of 11 instruments to explore Europa and the Jupiter System. The spacecraft is part of the joint NASA-ESA Europa Jupiter System Mission (EJSM). Image credit: NASA/ESA

Comments

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

It's about damn time! How about a probe to Titan on top of that? Obama was talking during the State of the Union about building interest in science to kids. What better way to inspire the youth than pictures of the shorelines of lakes on an alien world? Didn't Star Wars and Star Trek and all the associated imagery inspire today's scientists?

Europa, Titan, Enceladus. A least the current administration didn't eviscerate the JPL like they did NASA, & we can send unmanned probes to these worlds until we can get a manned space program started again.

By supporting projects like these, which can serve to be a spectacle for the general public, the administration is just putting up a show. There are NASA/ESA projects (like LISA) that actually aim to enhance the boundaries of science, which are being shelved because all that the public needs is a bit of scientific showmanship and governments and administrations duly comply.

@Syed:
A mission to Europa is 'enhancing the boundaries' of science, just in a different direction than projects like LISA. It would be foolish to put all your eggs in one basket and only focus on a single topic to advance, as breakthroughs come from many different and unexpected directions. You need to avoid a scatter shot approach but I think that NASA and the ESA are currently going a good job with the range of projects that they are funding given the money that they have to play with.

This Europa mission isn't some new fancy thing that they are dangling in front of people in order to win hearts and money either. It is a project that has been in the works for many many years.

I work with these projects. Believe me NASA is scrapping tens of projects for the sake of showmanship which by the way is a show of power than enhancing science even by a fraction of what so many other projects can. I dont want NASA to be concentrating on one thing at a time so sir. Its just that if your mission eats away 10 billion dollars of budget, ten projects like LISA are shut down. And even one LISA enhances the boundaries of science 10 times than the showmanship being put up for much more.

I work with these projects. Believe me NASA is scrapping tens of projects for the sake of showmanship which by the way is a show of power than enhancing science even by a fraction of what so many other projects can. I dont want NASA to be concentrating on one thing at a time so sir. Its just that if your mission eats away 10 billion dollars of budget, ten projects like LISA are shut down. And even one LISA enhances the boundaries of science 10 times than the showmanship being put up for much more.

Europa is the best candidate in our solar system to actually allow life evolution as we know it, and people dismiss it as if it's just another moon. Try understanding the possibilities that this finding could open.

I'm sure Samuel McConnel will agree. Jupiter Five (the fifth moon) is by far the most interesting at the moment... Those of you who haven't read Arthur C. Clarke's short story "Jupiter Five" need to do so immediately! It was immensely awesome! 2001 was pretty awesome, too.

Altogether in the A.C. Clarke books I've read, there was life on Mars, there will be life on Venus and Europa, alien technology has been left for us on Earth's moon, Earth will someday be killed off by a massive ice age (among other catastrophes,) and the second "Babylon" is going to evolve on a paralell Earth millions of lightyears away just as our Earth is wiped out. Did that about cover it?

About time? Where in the article did it give a time-frame for this mission? It's a guideline for mission from 2013 to 2023. I hope they build and launch it, but we have to finish paying for the JWST first (which will be great, but is hurting the budget and timelines for everything else).